Digital maps that can be stored on an electronic storage medium are used, for example, but by no means exclusively, for the operation of mobile or permanently installed navigation devices. In this case, the satellite navigation is based on the description of a geographic area such as, for example, the road network of Germany by a multitude of digital data sets.
In known navigation devices, databases that contain a multitude of such data sets are provided in order to describe the geographic area, wherein each data set describes an object of the map such as, for example, a road section or a terrain segment. These databases that are known from the prior art and contain data sets for describing map objects are referred to as original databases below. In this case, each data set for describing a map object consists of a certain number of attributes that can respectively assume a certain number of different attribute values. The attributes may consist, for example, of the geographic position of the map object and of the specification as a road section.
When operating devices, particularly navigation devices, or when utilizing such databases for describing a digital map, the data sets stored in the database need to be retrieved many times. During the composition of the graphic illustration of a section of the map, in particular, the data sets for describing the map objects in this section need to be read out of the database and processed by a graphics processor. If the map section changes in rapid succession, for example, due to the vehicle driving through the geographic area or the user manipulating the map section to be displayed, very many data sets with the attributes contained therein need to be read out and processed. In this case, the data quantities to be processed may be very large because the individual map objects need to be respectively specified by a multitude of attribute values and the new area itself contains a large quantity of map objects.
Consequently, very large quantities of data need to be managed when utilizing databases (original databases) known from the prior art for electronically processing digital maps, particularly for the graphic illustration thereof. This is a significant disadvantage because it is either necessary to provide a correspondingly large and fast main memory or the respective data needs to be very often read out of a mass memory and copied into the main memory.